Vacuum-tube device



E. R. STOEKLE.

VACUUM TUBE DEVICE.

APPLICATION FILED MAR,20,1916.

1,353,976. Patented Sept. 28,1920..

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E. R. STOEKLE.

VACUUM TUBE DEVICE. APPLICATION FILED MAR. 20, I916.

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E. R. STOEKLE.

VACUUM TUBE DEVICE.

APPLICATION FILED MAR. 20,1915- 1,353,976. PatentedSept. 28, 1920.

I 3 SHEETSSHEET 3- UNITED STATES PATENT mice Ertwnr n. s'ronxmfor NEWYomgx. Y., ASSIGNO'B 'ro WESTERN nLEc'rmc comrm, mconrom'rnn, 01 NEWYORKN, Y., A conrona'rlon or 'maw YORK.

vacuum-rum DEVICE.

Specification of Letters Patent. Patented Sept. 28, 1920,

Application flied March 20. 1916. Serial No. 85,457.

To all 'zohom it may concern:

Be it known that I, ERWIN R. S'ronKLn, a

- citizen of the United States, residing at New York, in the county ofNew York and State of New York, have invented certain new and usefulImprovements in Vacuum-Tube Devices, of which the following is a full,clear,

concise, and exact description.

This invention relates to thermionic vacuum tube devices and its objectis to construct a device of the above character which will have a muchlarger power capacity than those heretofore made.

In thermionic devices of the audion and other types in which two ormoreelements are used, one of the elements is heated'and becomes a source ofelectrons. The other element, called the plate, is usually left cold.Under-the action of an electric field, in which the cold element orplate is made positive, the electrons from the heated element traveltoward the plate and acquire a velocity, which, in case of a strongelectric field, may be exceedingly high. As a result of the electronicbombardment to which it is thus subjected, the plate becomes heated. Inthe case of such high vacua as are used in vacuum-tubes of this type, itis clear that this heat must be dissipated almost entirely by radiation.

It has been found that the capacity of these thermionic tubes .to handleelectric power is limited chiefly by the ability of the plate todissipate the heat due to bombardment, for when an attempt is made toincrease the output of'a given tube beyond a certain limit, the platemay be heated to such a degree that an excessive amount of occluded gasis liberated, thus diminishing the vacuum or the plate may actually beheated to its melting point, resulting in the tained by making thecontaining vessel ofthe vacuum tube of metal and using the metal vesselas the cold or pllate element. It

is apparent that the mu larger surface thereby afforded will permit of.greater radiation and at the same time further dissipation of heat ismade possible by convection.

To assist in this latter, it has been found desirable to cool the tubeby means of a fan or by immersing the tube in water, or oil, or othersuitable cooling agent.

The invention will be better understood by reference to the followingspecification and accompanying drawings in which Figure 1 shows alongitudinal sectional view of one embodiment of this invention, withcertain parts shown in perspective. Figs. 2, 3 and 4 show similar viewsof various modifications. Fig. 5 is a similar view of a furthermodification, and Fig. 6 is a section taken on the line 66 of Fig. 5.Fig. 7 shows in detail a method for sealing in electrodes and forobtaining connection to an evacuating pump.

Referring to Fig. 1, 10 shows a metal containing vessel. In practice ithas been found satisfactory to make this vessel of copper, althoughother metals may be used without departing from the spirit of theinvention. In this vessel the bottom may be of a separate piece of metalwhich is hard soldered to the cylindrical portion 10, or the wholevessel may be madeof one piece of copper by spinning. This latterispreferable if possible in order to diminish the probability of leaks. Asis usual in vacuum tubes of this type, there is a filament element 11and a grid element 12, the grid being preferably covering 15, which inthis modification should be of insulating material, such for instance asplate glass. Metallic rings 16 and 17 are used in connection with boltsand nuts 18 and 19 to hold the plate 15 firmly against the flange 14:.In order to prevent leakage there is placed between the plate 15 and theflange 14, a lead gasket 22. Above the Iilate 14, there is placed a leadgasket 23. he lead gasket 22 is here shown as having a number ofcircular concentric grooves which, upon the application of pressure bymeans of the bolts and nuts 18 and 19, will spread slightly and make avery close and metallic rods 25, 26 and 27, which serve as leading-inconductors and as means for evacuating the vessel. Connected to themember 25 is shown a rod 28, from which extends a plurality ofconducting wires 29, which make suitable contact with radiating members30, thereby affording a uniform distribution of current to the filamentelement 11. As shown in the drawing, this -'filament member 11 consistsof a plurality of filaments arranged in parallel, and held in positionby metallic. rings 31. These metallic rings 31 are suitably supported bymeans of radial members 30, 34 and 35 attached to a glass tube 33.Through the center of this glass tube 33 extends a conductor which isattached to the member '26. The lowest member 31 is electrically "as ameans for'attachment and as a means for spacing the various turns of thespiral grid. Two similar members 38 are also shown for further assistingin the proper spacing of these grid turns, and for assisting also inholding the grid in proper position, this last .being accomplished byhaving the upper ends project into small holes drilled partly throughthe plate 15. The grid is held firmly against the glass plate by springmembers 37.

In such vacuum tubes as here described, it is frequently desirable tohave a vessel evacuated to the very highest degree possible, and inorder to maintain such a vacuum, the greatest precautions must be takento prevent leakage. In the case of the members 25, 26 and 27, thisprevention of leakage is obtained by supplying these members each withshoulders 40, and between theseshoulders and the plate 15 are placedlead washers 42. Additional lead washers 42 are supplied to the otherside of this plate 15, and close and intimate contact such as willprevent any leakage, is then obtained by firmly screwing upon themembers 25, 26 and 27 suitable nuts such as shown at 41. To provide forthe exhaustion of this tube, the member 27 is tubulal, as seen at 45.Into the upper end of this is placed a tapered glass tube 46, which fits.snugly, by means of a ground joint with a corresponding taper 47 in themember 2-7. This tube 46 is then connected to any suitable evacuatingpump, and when a sutlicient degree of vacuity has been obta1ned,-thetube is sealed off. In this way the member 27 serves both as aleading-in conductor to the grid, and as a tube, by means of whichevacuation .is obtained. The members 25 and 26 are shown with holes 49drilled in a short distance to form a suitable receptacle for electricalleads.

The method of using the tube thus far described is identically the sameas that of the usual thermionic devices of the audion type. The members25 and 26 serve as leads for the filament heating current. The member 27serves as a terminal for the grid, and the containing vessel serves asthe plate, contact being made at any suitable point.

In Fig. 2 there is shown a modification of the form shown in Fig. 1. Theoutside vessel construction is essentially the same and consists of themetallic vessel 51 within which is placed a filament 52 and a grid 53.In this case the filament 52 consists of a U- shaped filament, themembers 68 and 69 serving as leads therefor. As in Fig. 1, there isshown on the vessel 51 a flange 55, and the vessel is closed with asimilar glass plate 56, this glass plate being held tightly by means ofmetallic rings 57, 58 and screws 59. Suitable lead gaskets 60 are alsosupplied, which may be of the simple form shown in this Fig. 2, or ofthe grooved type shown in Fig. 1. As in the previous figure, three holesare drilled in the plate 56 through which extend the members 67, 68 nd69. As in the former figure, these places are made air-tight bysupplying shoulders 71, lead gaskets 72 and nuts 73. The terminal member69 is shown as tubular in order that a tapering ground-glass tube 76 maybe fitted into a corresponding taper 75, thereby affording means forevacuation. The grid 53 is electrically connected to the member 67. .Thelower ends of this grid are. properly spaced by means of a glass spider63, which serves as means for properly spacing the members 62. Thistripod 63 is further held in proper position by means of glass spacingmembers 64. In order to hold the filament in place and at the same timeto allow for such expansion as takes place upon heating, there is showna spring member 77 extending from the turning-point of said filament tothe tripod 63. The operation of this formof device is the same as inFig. 1.

Fig. 3 shows a further modification in which the method of sealing thetop of the metallic vessel 51 is changed. In this case the top consistsof a glass member which supports the grid 53 and the filament 52. As inFig. 2, there is also shown the spacing tripod 63 with the spacingmembers 64. In this form,oterminals from the filament are sealed throughthe glass cover, as shown at 'upwar 82"and 83 and a similar terminal forthe grid is sealed through, as shown at 84. A carefully fitted andground joint connection is made between the vessel and the glass top 80,this being shown at 85 and 86. Throu h the center of this glass topextends a glass tube 87, by means of which evacuation maybe obtained.

In view of the very considerable heating of 51 which is required inorder to drive off occluded gases, it is necessary to provide coolingmeans near" the upper portion of the metal tube in order that the glasstop shall not be subjected to great changes of temperature. Such acooling vessel is shown at 89 and would in general be applied to allthree of the modifications thus far shown.

Fig. 4 shows a tube of smaller diameter which is particularly adaptedfor smaller power than is intended in the case ofthe previous figures.In this Fig. 4 there is shown a metallic tube 90 with tapered ends 93into which fit glass members 91 and 92, which have tapered ground ends94, making close and intimate contact with the ends 93. In addition tothese ground joints, it is in general desirable to further improve theseal by means of suitable sealing compounds. Through the center of thetube extends a filament 96 which is supported from each end by metallicrods 97 and 98. From the member 97 extend leading-in wires 100, andsimilarly from the member 98 extend wires 101. In order to allow for theexpansion of this filament, a spring member 103 is connected between themembers 91 and 98.

The grid member is here shown at 105, and is of substantially the sameform as heretoforedescribed, that is, it consists of a metallic spiralhaving the turns roperly spaced by longitudinal rods 106. 0 each end ofthis grid, as thus made up, is secured a glass spacing and supportingmember 107 and 10S, and the grid element as a whole with the spacingmembers may then he slipped into the metal tube 90, where it is held inproper position. The grid 105 has a leadingin wire 109.

Fig. 5 shows a further modification, in which a flattened metalliccontaining vessel 1-10 is used instead of the circular cylinders shownin the earlier figures. The purpose of flattening this tube, which isclearly shown in Fig. 6, is to bring the grid and filament closer to theplate element, thereby decreasing the voltage required to carry theelectrons from the filament to the plate, or, for a given voltage,obtaining a larger transfer of electrons and therefore a larger outputcurrent. In this modification there is also shown a metal top 111instead of the glass top of the prior figures. This cover 111 ispreferably hard soldered to the'vessel 110. On the inner side of thismember 11 there is secured, by suitable means, members 112,

which act as supports for insulating rods The grid consists of a network118, which surrounds the filament members, being disposed between saidfilament and the plate element 110, and while a grid of one particularmesh is shown, it is obvious that the grid may take a large variety offorms of mesh and still give the desired results. A small hole is showncentrally located in the member 111, and into this hole there issecured, by hard soldering, a platinum collar 121. This collar, in turn,is sealed into a glass member 122, from one side of which projects anarm 123 leading to any suitable evacuating pump. Conducting w ires 124and 125 are sealed through the member 122 as shown at 126, and, afterpassing through glass tubes 127, these conductors lead to one or theother of the bus-bars 115, thereby con stituting suitable leads for thefilament heating current. Inasmuch as the individual filament elementsare connected in parallel, it is obvious that a heating current ofconsiderable magnitude will be required, and in order to preventexcessive heating at the point where the conductors 124 and 125 aresealed through the glass, it is desirable to break these conductors upinto a plurality of smaller conductors sealed in at points slightlyseparated the one from the other, as shown at 126. A conducting member128 metallically connected to the grid 118 serves both as a leading-inconductor for said grid and as a partial support therefor. In order toimprove the insulation for this member, a glass tube 129 may cover thispart, as shown.

For the protection of the glass member 122 against mechanical shocks, itmay be desirable to supply a metallic protecting member 131, which ishere shown as secured to the member 111 by means of screws 132. Holes134 may also be supplied to permit circulation of air or other coolingmedium. In order to assist further in holding the filaments and grid inthe proper relative position there are shown glass spacing members 136.

he method shown in this figure of making a junction between a massivemetallic member, such as 111. and a glass member 122 by means of anintermediate platinum collar has been found very useful and suit ablefor much of this work. This is further exemplified in Fig. 7, whichshows a metallic vessel 140 having a metal top 141 instead of a glasstop. It is aparent that in this. case special provision must be made forinsulat ing the various leading-in terminals, and this is accomplishedin the manner indicated. Three holes are drilled through the top member141, and platinum collars 143 are hard soldered to each of these. Thesecollars in turn are sealed into glass tubes 14-1, 145 and 146 ofsuitable dimensions, advantage being taken of the fact that platinum hassubstantially the same coeflicient of expansion as glass. Leading-inconductors, as shown at 148 and 149, may now be sealed through the glassmembers 144 and 145. The tube 146 may be used for evacuation byattachment to any suitable evacuating pump. and this tube may further beused for a leading-in conductor. Such an expedient may well be used inplace of the glass top shown in connection with Figs. 1 and 2.

In all of the figures the filaments are shown as of the now well-knownoxid covered twisted filaments, described for example in patent toNicolson 1,137,275, April 27, 1915, but it is to be understood that anyother form of filament suitable for acting as a source of electrons maybe used without departing from the spirit of this invention.

It should be mentioned that, during evacuation of these tubes, theyshould be heated to a temperature well above the temperature at whichthey are to be operated. This is for the purpose of driving off occludedgases. This heating may be accomplished in any suitable manner such asplaying a Bunsen flame over the tube or by using an electric furnace.

The metal to be used in these containing vessels may be any which willstand the mechanical stress of the atmospheric pressure and which willhold a good vacuum. Copper and brass are good and have been used, buttungsten and molybdenum are peculiarly suitable because of the hightemperature to which they may be heated in order to drive off occludedgases and because under operating conditions they do not give offoccluded gases and thereby destroy the vacuum.

While in some of the tubes shown the metallic vessel completely inclosesthe tube and in others does the same with the exception of one or bothends, it is to be understood that a smaller portion of the con-tainingvessel may be of metal, but in any event the invention is the same,namely, that the plate is made a part of or the whole of the containingvessel whereby the large amount of heat generated on the portionconstituting the plate element may be readily and rapidly removed.

It is obvious that while a number of forms of tubes have been describedin detail that a very large number of variations and modifications maybe used without departing in any measure from the spirit of thisinvention, which consists essentially in the construction of an audiontube, in which the cold or plate element constitutes the containingvessel, or one or more of its walls 01' any part thereof, whereby a'verylarge amount of heat energy may be dissipated without unduly raising thetemperature of the various parts of this vacuum tube.

What is claimed is:

1. A vacuum tube comprising a filament and a plate. element, a pluralityof external terminals for said cathode, the plate element consisting ofa metal of the tungsten family and constituting the containing tube.

2. A thermionic device of the audion type,

' comprising a metallic containing vessel, a

source of electrons within said vessel and an element for controllingthe electron current between said source and said metallic vessel.

3. In a thermionic device of the audion type, an evacuated metallicvessel, a heated element within said tube, a source of electromotiveforce connected between said heated element and the metallic vessel forproducing a space current therebetween and a grid element within saidtube for controlling said space current.

4. In a thermionic device of the audion type, an evacuated vessel of ametal of the tungsten family, a source of electrons there in consistingof a plurality of filaments connected in parallel, and a gridelementdisposed between said ovessel and said filaments adapted to control theflow of said electrons to said evacuated vessel.

5. In a thermionic device of the audion type, a flattened metallicvessel adapted to be evacuated, aheated filament constituting a sourceof electrons, and a grid element disposed within said vessel andadjacent to said filament, adapted to control the flow of electronstherefrom.-

6. A thermionic device of the audion type comprising a containing vesselof a metal of high melting point, a source of electrons within saidvessel, and a grid element for controlling the electron current betweensaid source and said metallic vessel.

7. In a thermionic device of the audion type, a flattened metallicvessel adapted to be evacuated, a source of electrons therein consistingof a plurality of filaments connected in parallel, and a grid elementwithin said vessel and adjacentto said filament adapted to control theflow of electrons therefrom.

8. A thermionic vacuum device comprising a heated element, a plateelement and a containing vessel a wall of which comprises said plateelement, said heated element hav- 'current for heating said heatedelement to make it thermionica-lly active.

9. A thermlomc vacuum device comprlsing an evacuated vessel, a heatedelement and 'a plate element, a plurality of external terminals .forsaid heated element, said plate element comprising a portion of-saidvessel.

10. A' thermionic vacuum tube comprising.a filamenta cathode and a plateelement, the plate e ement constituting the containing tube, saidcathode havin a' plurality of terminals extending outsi e of said tubeand adapted to receive current for heating said cathode to make itthermionically active;

11. A vacuum tube comprisin element and a plate element, a p urality ofexternal terminals for said heated element, the plate element consistingof a metal and constituting the containing tube.

12. An electron dischar e device comprising a cathode and an anode, saidanode surrounding said cathode and having opp sed parallel surfaces,said cathode extending aterally beyond the center of i said electrodes.a

13. An electron discharge device com 'rising a cathode, a gridsurrounding'sa' cathode, andan anode surrounding said grid, said anodehaving opposed parallel surfaces, said cathode extendm laterally beyondthe center of said electro es.

14. An electron discharge device comprising a cathode, a gridsurrounding said cath'ode, and. an anode surrounding said ,grid, saidgrid and anode having opposed parallel surfaces, said cathode extendinglaterally beyond the center of said electrodes.

15. An electron discharge device comprising a cathode having a pluralityof straight filamentary sections, a grid surroundm saidI cathode, and ananode surrounding sai g 16. An electron discharge device comprising acathode having a plurality of straight filamentary sections connected inparallel,

and an anode surroamding said cathode.

17. An electron discharge device comprising a cathode having a pluralityof straight filamentary sections, a grid. and an anode surrounding saidcathode, said electrodes presenting parallel surfaces.

18. An electron discharge device comprising a cathode and an anodepresentin par-' allel electrode surfaces, and one ofsai electrodessurrounding the-other.

- 19. An electron discharge device comprising a' cathode, an anode, anda '41, said electrodes presenting parallel sur aces, and one of saidelectrodes surrounding the other two. a

20. An electron discharge device compris ing a support, a plurality ofparallel cona heated nected filamentary sections supported thereby, gridand anode electrodes surrounding said sections.

21. An electron dischar e device comprising a planary cathode having aplurality of parallel connected filamentary sections, and an anodesurrounding said sections.

22. An electron discharge device com rising a lanary cathode havinga;pair of usbars, lamentary sections extendln therebe tween, a gridsurrounding said cat ode, and an anode surrounding said grid saidelectrodes resenting parallel electrode surfaces.

23. electron discharge device comprisan anode in the shape of aflattened cy inder, and a cathode extending laterally beyond the axis ofsaid cylinder.

24. An electron discharge device comprisin in er, grid and cathodeelectrodes within said anode and extending laterally beyond the axisthereof.

25. An electron discharge device comprisin an anode in the shape of aflattened cylin er, a grid therein having a similar shape, and a cathodehaving a surface extending laterally beyond the axis of said anode.

26. An electron discharge device comprisin an anode in the sha of aflattened *cyl- Q in er, cathode-and grid said anode forming the wall ofan evacuated vessel in which said cathode and grid are mounted.

27. An electron dischar e device comprising anode, cathode and gridelectrodes, said cathode comprising a plurality of sections connected inparallel,- one of the lead wires of said cathode having a plurality ofstrands which are separately sealed into the wall of the evacuatedvessel in which said cathode is mounted.

28. A vacuum tube comprising an electrode, a metallic container for saidelectrode, a top for said container hard soldered thereto, saidelectrode being supported by said top, a' glass tubular portionprojecting from said top, lead-in wires for said electrode, said lead-inwires being sealed in said.

tubular portion and a seal between saidtubular portion and said topcomprising a substance having substantially the same temperaturecoeflicient as glass J 29. A vacuum tube comprising a filamentaryelectrode, a metallic container therefor, a top for saidcontainer hardsoldered thereto, a framework supported by said top and supporting saidelectrode, said top havin an opening, a metallic collar above saiopening and fastened to said top, a tubular portion sealed to saidcollar, said'tubular portion being of a substance having propertiessimilar to glass, said collar having "a: temperature-.coeflicientsubstantially the same as said tubular portion.

electrodes therein,

A vacuum tube comprising an alon an anodein the shape of a flattened'cylgated envelop, an' electrode ated envelop having opposed parallelsur-I aces andan electrode supporting framework attached to' one end ofsaid envelop,

- laterall projecting arms on said framework metal having a 33.A-vacu'um tube adapts to slidably contact with the ogposed arallelsurfaces of said envelop, sa1 arm's being located near the unattachedend-of said envelop.

32. A vacuuth tube comprising an envelop having a main portion,anelectrode supporting framework attached at one end of said envelop,vand projectionson said framework near the unattached end and adapted toslidably contact with said main body portion for spacing said frameworkwith respect to said envelop.

comprising an envelop having a main body portion, an electrodesupporting framework attached at one end of said envelop and lateralprojections on opposite sides of said framework near its unattached endand contacting with the body portion for spacingsaid framework withrespect to said envelop.

walls of said main 34. A vacuum tube,. an electrode therein, aleading-in wire for said electrode, a glass member in to which said wireis sealed, a portion of the wall of said tube being of glass membe sealsof parallel bus-bars, tary cathode sections connected in coeflicient ofexpansion different'from' that of said glassmember, and.

a platinum tube sealed at one end of said 4 metal portionand at theother end to said 35. A thermionic device comprising -a cathode, :ananode, said anode eonstitutin' a portlon of the-containing wall of -sai4 device, a lead-in wire for said cathode, a glass member into whichsaid wire is'sealed, said anode bei of metal aving a c0efii-- cient ofexpansion different from that'of said lass member, and a platinum. tube5 at oneend to said anode and at the other end to said glass member.

36. A'thermoinic device compr a plurality'of lamenarallel thereby, andan anode having a c lmdrical surface associated with said catho e.

37 A thermionic device comprising a pair of parallel bus-bars, aplurality-of filamentary cathode sections connected in parallel thereby,an anodehavin a cylindrical smirface associated with said cathode and agrid electrode between said cathode; and said anode. I

38. A vacuum tube comprising a filament 'I and a cup-shapfd metallicanode, said anode cogztitutmg t e containing wall of said 39. Anevacuated vessel com rising a filament, a cylindrical anode an an 1n al-'7 metallic closure at one end thereof, said anode constituting aportion-ofthe c0ntain-- wall of said vessel.

- n witness whereof, I hereunto subscribe my name this 16th da ofMarch-A. D. 1916. 7

. R. STOEKLE.

a pair

